Dear student,
1. electron deficient compounds of Hydrogen : It is the type of hydride in which the no. of electrons present are less then the required no. of electrons. eg:- B2H6
2. electron precise compound of hydrogen: It is the type of hydride in which the no. of electrons present is equal to the no. of electron required. eg:- CH4
3. electron rich compounds of hydrogen : it is the type of hydride in which the no. of electrons present are more than the no. of electron required. eg:- NH3
Regards